Credit pool is getting failed on Stage

When Doing Election Import Credit Pool Getting Failed.
tried on More than two company.
Refer below error log and attached screen shots:

ErrorID : 0
ErrorSource : ControllerAppTier.Save->WORKTERRAControllerAppTier.Save->ExecuteImportDTS.CreditPoolAllocationAfterImport
ErrorMessage: Index was outside the bounds of the array.
StackTrace: at WORKTERRA.Shared.WORKTERRAControllerAppTier.Save(WORKTERRAControllerWebTierEntity objWORKTERRAControllerWebTierEntity)
at WORKTERRA.ControllerAppTier.Save(Int32 intProjectsId, String strInput)
TargetSite: System.String Save(WORKTERRA.Shared.WORKTERRAControllerWebTierEntity)